It's Just That Complicated!
by numbertenthirteen
Summary: [College AU] A new (hot) substitute teacher walks in. Bonnibel instantly likes the teacher, Marceline is jealous and Fionna is in love with Marceline. The substitute teacher likes Fionna. THIS IS SO COMPLICATED!


**Pompeii**

"Marceline? You're out of trance, again." her best friend since childhood said, the raven haired girl shook her head and smiled sheepishly, "Sorry about that, what is it again?"

With a sigh, her pink haired friend started discussing, "this Saturday is Leon's birthday, can you come?"

Leon, Bonnibel's younger brother.

"Uh, sure..." she muttered, "What will I bring then?"

Bonnibel pondered for a moment, "Well, she likes your music, so just sing a song for him and he'll like it." she smiled. Marceline nodded and ran a hand to her black mane and stood up, "Want to have lunch then?"

"Sure thing, I think they are now at the rooftop, waiting for us." she offered her hand to Marceline and she gladly took it.

Marceline Abadeer daughter of the city's most feared man because he's "Lord of Evil" in Nightosphere Inc, a company that makes guns and other weapons. At the age of 14, she started helping in the family business, making her mature in her decisions and in life. But there's one thing that she can't be mature about.

And that is her love life.

The love of her life.

Bonnibel Bastille, daughter of a neurosurgeon and a food scientist. Just like her parents, she grew up to like, no, love Science. Making her study Biology and a minor in Medical Technology.

They've been friends since high school, they also went to the same university in college, afraid of being away to each other. So, Marceline took a major in Business Management and a minor in Musical Studies because she's rich and she wants to.

Well, she started liking the pink haired girl when they were in their junior year of high school, when she was so vulnerable because her mother died, the pink haired girl was there for her. Sleeping on her bed, and to cuddle her.

Marceline doesn't really believe in love, but there's something about her best friend that she always like. Something about her that she just can't let go.

Maybe because she's afraid that no one would be there or maybe because of the attachment that they have for each other, whatever it is, it's bothering the hell out of her.

Now that they're seniors in college, life was a little bit of easy for her, but not for the pink girl, she still needs to finish two thesis works and needs to work on her speech.

She's fucking running to be the valedictorian.

While her? she's just the salutatorian, she's okay with being number two. As long as she's next to the pink girl, it's alright.

"Did you text them?" Marceline asked, Bonnibel shook her head and sighed, "they said that they'll be busy and may not be able to join us."

Marceline nodded, a small jolt of happiness creeping up to her, at the fact that they'll be eating alone in their favorite restaurant excites her.

"Shall we go to Stacy's then?" she asked, the pink haired girl nodded, "Sure, let's go Marcy." she smiled.

Marceline almost flipped the fuck out because of that beautiful smile.

Bonnibel's sporting a white dress with black polka dots and a caramel colored cardigan with black doll shoes and a white ribbon on her hair as she braided and let some strands loose on her side. She was really beautiful with those cerulean blue perfect eyes with that cheeky smile and just, god!

Marceline shook her head and chuckled, she's going crazy for this girl.

She was only wearing a plain white shirt, blue faded jeans with her black button up tied on her hips and black boots.

Marceline smiled at her best friend who was now tip-toeing in the street, she was cute. Though she was now 21, she's still be considered as cute because she's just cute. And Marceline finds it crazy.

Or she's just crazy.

Either way, she's going crazy for this girl.

Bonnibel knows about Marceline's sexual orientation, never really cared because she was her friend and it will never change no matter what Marceline is. Bonnibel also has a series of girl crushes, which made the raven haired girl jealous.

What does she do when Bonnibel flirts?

She simply glares at the flirt's recipient and it would run away, leaving a dumbfounded Bonnibel and a smirking Marceline, she knows that it's wrong, it is. But she just can't live with Bonnibel being hurt because of love.

Also, Bonnibel gets jealous when Marceline hangs out with her other friends, and she likes it. She likes the attention her best friend is craving from her.

"What do you want to order?" Bonnibel asked, Marceline shrugged her shoulders, "the usual."

Bonnibel bits her lip, "we'll be taking the usual." she winks at the waitress, also known as Keila, Marceline's bandmate.

"mm 'kay." with that her friend walks away leaving Marceline staring at her best friend.

"Hey, Marcy.." she called as she opened her laptop, Marceline closed the tabs on her phone and looks at her with a distinctive "yeah?"

Bonnibel tastes her mouth before speaking, "My love life has been full of failures, anyone that I flirt with either runs away or is not interested. What is up with me anyway? I'm smart, they even call me beautiful and I love pink!" she raises her hands to add effect, Marceline laughed.

"Not that you're smart or beautiful, just think of me, I don't even have a freaking love life and I'm happy with being single." she said coolly.

"But it's you," she pouted, "you can have anyone you want.."

_I don't.. but even if I do, you can never be mine. _Marceline thought.

"Nah, it's not me, it's you. You'll just have to wait for that special someone." she smiled, trying to calm her friend who nodded.

Bonnibel sighed, "There's this Summer Love Event that will be happening here in Candy Groves, I want a date."

"Well, you can go with me?" she said, nonchalantly. They always go with each other, even in prom. She disguised herself as a man because she doesn't want someone to go with Bonnie and the same thing goes to her.

"But you said that you'll be going to Nightos?" she asked, Marceline shook her head, "I can reschedule."

"Really?"

"Really." she smiled, the pink girl almost jumped on her seat when their foods had arrived.

Keila winked at Marceline, "Here's your usual order with the usual waitress to serve you."

the two of them laughed, because they know that Keila hated her job.

* * *

><p>x-x-x<p>

Marceline slowly sits down on her class, as she waits for their professor. When Bonnibel came in and sits next to her, "Morning, Marcy." she smiled, Marceline smiled and greeted her back, "Good Morning, Bon."

Bonnibel took the subject as an extra credit to spend time with Marceline, because that's what best friends do, right?

When a raven haired man walks in, with black button up, red tie, with black slacks and shiny black shoes, his eyes marveling at the sight of 30 students in front of him. He was carrying a black book and adjusted his tie as he smiled at everyone and introduced himself, "I am Marshall Lee, Mr. Braun is excused and I am here to be his substitute, I am a fresh grad of Philosophy and I'm pretty sure that I know the basics with this subject. If you didn't catch my name, let me write it on the board." he said, he noticed that the students were silenced by his presence, he smirked.

He walks towards the huge black board and wrote his name in a neat manner, "Marshall Lee."

He went back in front and sat on the table, his legs crossed and opens his black notebook, "Today happens to be an oral recitation, are you all prepared for this?" he asked, his red eyes searching the area when his eyes stopped on a pink haired woman who was furiously blushing and to the woman next to her, who has a black hair and green eyes that seems to be inflicted at him.

He smirked.

He drifted his attention back to the notebook and said, "Who is Lucky Strike Parker?"

A purple haired woman stands up, she's a little bit of chubby but by the looks of it, she seems sociable because of the bling-blings that she wears.

"Yes, Mr. Marshall?" she asked, in a flirty tone.

He nodded and then said, "Who is Karl Marx?"

the whole room went silent.

Marceline on the other hand wasn't impressed at the substitute teacher._  
><em>

"He's so hot, my glob!" Bonnibel whispered at her, Marceline on the other hand shrugged her shoulders, "Nah, he's okay."

Bonnibel playfully jabbed her on the arm, she remained emotionless, piercing the shit out of that man, through her eyes of course.

If looks could kill, Marshall Lee would be dead.

"How about a maiden named, Bonnibel?" he asked, and with like a bubble popping, Bonnibel immediately stood up with a huge smile on her face.

Marshall blinked and smiled at her, "Who is Thales?"

"He is the father of Philosophy," she immediately answered, as expected, the professor smiled at her and nodded, "very good, please introduce yourself."

"I am Bonnibel Bastille, 20 years old, and I'm taking this subject as an extra credit." she smiled, Marshall smiled back and motioned her to sit down, "Thank you for that, Ms. Bastille, how about the woman sitting next to you?"

at that, Marceline grumpily stood up and nodded, "Hello sir,"

"Hello, are you Ms. Abadeer?"

she nodded, of course, he knows who she is. Everyone does.

"yes, that'd be me." she shrugged her shoulders, then she crossed her hands and looks at him in disdain, the teacher nodded and asked, "Well, it's stated here in the notebook that you're not needed to answer these questions," with a sigh, he closed the book and looks at her, "you may now take your seat... how about Ms. Peppera?"

* * *

><p>x-x-x<p>

"Hey, Bonnie!" Marceline called her best friend who happily turned her back around her, Marceline jogged her way to her best friend and smiled, "So what movie will we be watching tonight?" she asked as she finally was on Bonnibel's level of stairs.

Bonnibel let out a sigh, "Sorry, Marcy... but I can't go for tonight's events.." she pouted, Marceline tilted her head, "Eh, you never miss any of our movie nights... why?" she inquired, trying to fight the sinking feeling that she now felt that her very own best friend rejected her.

"Marshall wants to go to movies with me." she smiled dreamily, Marceline blinked.

"What."

The pink girl smiled, "Yes, he asked me out and I said yes." her smile widened and she started skipping toes to the gate, Marceline on the other hand froze.

"Marcyyyy, let's go!" She called her best friend when she arrived at the gate, Marceline's senses came back and jogged her way to her best friend.

Marceline then grabbed her friend by the shoulder, "What the hell, you never miss any of our movie nights and now you're ditching me because a guy asked you out?"

"Marceline," Bonnibel started as she caressed Marceline's cheeks who became calm, "please, let me go just this time? I never went out to any dates since 3 years, alright?" she smiled, as she kissed Marceline on the nose and giggled, "I'll be seeing you tomorrow?"

Marceline fought the frown that her face would like to make, "uh, sure. You go have fun." she faked a smile.

"You're the best!" as one final goodbye, she kissed her best friend's cheek and waved at the black car in front of the school, she was greeted with men in suits and they bowed slightly at Marceline who waved at her.

Marceline sighed as she went to an alley near the school to catch some hot coffee.

"Yo, Marcy!" someone called her when she was about to enter the small coffee shop, she turned her back and saw a blonde girl who was wearing their school uniform (white button up, black blazer, red skirt, white knee socks, and red tie) she was wearing her usual blue hoodie, (so she's not wearing the school blazer) and jogged her way towards the raven haired girl.

"Hey, Fi, sup?" she smiled at the younger girl who is now behind her, since she was taller (Fionna's just Marceline's chest level) she patted the blonde's head and the other girl giggled.

"Stop doing that!" she protested, "you're just a year older than me!" she pouted, Marceline shrugged her shoulders, "still doesn't matter, I'm taller than you."

the blonde gave out a huff and went inside, Marceline shook her head as she followed suit.

"So, what do you want to eat?" Fionna asked her, Marceline replied, "cho-nut and a warm coco for me, I'll go find us a table?"

the other girl nodded and so Marceline went out to find a seat near the window, she sat there as she sighed and let out a huge breath.

_so she's out on a date with our professor, way to fucking go. How the hell did he even ask her out? me and Bonnie are together ever since we got out? and she calls him Marsh? are they even now close? but.. what if he'll take her away just like that? I've been with her almost all my life, watched movies with her, and we even went to different countries only to lose her for a guy who just asked her out on a fucking date?!_

Marceline gritted her teeth at the thought of Bonnie being away from her, but that's just what life is. It is cruel in any ways possible.

"Hey," Fionna arrived with their food, Marceline almost jumped at the distraction but she gladly accepted the tray and laid it on the table.

Fionna took her phone and started typing, while Marceline recomposed herself and took a bite of her donut and sighed.

The blonde noticed the constant sighing and have observed that the raven haired girl was not being accompanied by a certain pink haired girl.

"Where's BB?" she asked, Marceline looks at her before sipping her coco and then again, does it again. She shrugged her shoulders, "has an appointment with a guy,"

Fionna blinked, "she ditched you for a guy? well that's new." she raised her brows, Marceline bit her donut and nodded, "It really is new, but then again, she has her own life, so might as well respect that." she smiled, Fionna shrugged and cut a piece of her cake and started eating it.

"Really is new, that's why I saw her earlier with a guy, that must be him, eh?" she asked, as she sipped her orange juice, Marceline nodded and continued eating when she asked, "You know the guy she was with?"

"Yeah, it's Marshall Lee, maybe handsome to look at but he's an all around playboy, you should probably do a background research about him."

Marceline nodded, "I know who to call about this one." she winked, Fionna looked away as she tries to hide the blush and nodded.

"Why are you blushing?" the raven haired girl asked, Fionna shook her head as she covered her face using her hands, "No, nothing in particular, I need to go to the bathroom!" she jumped out, and ran towards the comfort room, Marceline was left dumbfounded as she pressed a purple contact in her phone and waited for a certain someone to answer.

* * *

><p><em>WHAT THE HELL, FIONNA! YOU ALMOST SHOWED YOUR INTENTIONS! REMAIN CALM, I REPEAT REMAIN THE CALMNESS! BUT, HOW THE HELL CAN I BE CALM WHEN WHEN WHEN SHE JUST WINKED AT ME, DAMN IT WAS SEXY AS HELL BUT NO, ABORT MISSION TO KISS HER. IT'S TOO MUCH! TOO MUCH! <em>

Fionna almost jumped when someone tapped her from behind, it was her classmate in Pysch203, Bernadatte Flamehart.

"You're so red, what's up?" she asked, her red hair puffing out because of the curls and it always shines because of its fiery red color.

Fionna opened her back and took out her baby powder, "Not- nothing.."

"Eh, I saw her outside, you're with her?" she asked, her other brow raised at her inquiry, Fionna nodded. "Uh.. yeah.."

The redhead laughed, "and you're blushing because?"

"She winked at me.." the blonde confessed, Flamehart laughed and patted Fionna's back. "You're like a high schooler. too cute."

the blonde huffed, "I am 20 for Pete's sake!"

"You gotta prove it to me, girl." Bernadette smiled, Fionna rolled her eyes, "Sure thing, FP."

the redhead laughed at her nickname, "You do know that she's waiting,"

"of course, I do."

"And?"

"That's why I have to go." Fionna giggled as she winked at her friend before heading out to see a bored Marceline playing with her food.

* * *

><p>x-x-x<p>

"Thanks for the time, Fi." Marceline smiled as they arrived outside Fionna's dorm, the blonde nodded.

Fionna managed to put a smile on her face, "thank you, too... are you really sure that you don't want coffee or anything?" she asked, not wanting to end the time that she spent with her crush since high school.

"I'm good, thanks tho." she smiled back, the blonde looks at the ground, her throat now dry because she was shy.

Now playing with her feet, Fionna blushed. _Oh god, oh god, she must think that I'm weird or she might figure out that I like her! _

"So, we'll call this a night?" the blonde looked up and saw the raven haired girl smirking at her, "Yeah, thanks." with that, Marceline patted Fionna's head and kissed her forehead.

"Good night, Fionna." she smirked before waving goodbye and walked away from the blushing blonde girl.

* * *

><p><strong>AN- i have no idea what i just wrote, but i kinda like the concept of this story**

**anyway**

**feel free to read some of my stories, you MIGHT like/love them**


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